New insights into tissue-specific responses and interactive characteristics of crop-microbe “One Health” system to soil chromium and ofloxacin pollution

Abstract This study firstly investigated the tissue-specific responses and interactive characteristics of the crop-microbe system to co-pollution with ofloxacin (OFL) and chromium (Cr) in soil. The results emphasized the hormesis effect induced by low-dose OFL (1 mg L -1 ) on ginger plants subjected to soil Cr stress. However, high-dose OFL (100 mg L -1 ) and Cr co-stressed plants exhibited reduced growth, root activity, antioxidant enzyme activities and photosynthesis-fluorescence performances, while the reactive oxygen species (ROS) reflected by O 2 ·- and H 2 O 2 significantly increased up to 43.34% and 78.63%, respectively, compared to other treatments. In addition, high-throughput sequencing indicated that OFL influenced rhizosphere microbial diversity, composition, and evolution, favoring Proteobacteria proliferation under co-pollution. Meanwhile, root exudate patterns shifted, with humic-like exudates, potentially interacting with pollutants and microbes. Notably, enrichments of antibiotic resistance gene ( qnr S) in edible rhizome and potential pathogenic bacteria in ginger rhizosphere were observed under OFL and Cr co-pollution, raising environmental and food chain concerns. Through structural equation modeling, we quantitatively established correlations within soil-crop-microbe factors, emphasizing their interconnected nature. Overall, this study sheds light on the complex responses of the crop-microbe system to OFL and Cr co-pollution, highlighting the importance of understanding pollutant interactions for enhancing plant resilience and mitigating environmental risks. Highlights Revealed a hormesis from low-dose OFL on Cr-polluted ginger, enhancing resilience. Rhizosphere microbial composition shift under co-pollution, favoring Proteobacteria. qnr S and potential pathogens increased under co-pollution, posing food chain risks. Structural equation modeling quantified correlations in soil- crop-microbe factors. Clarified crop-microbe “One Health” interactions’ role under Cr & OFL co-pollution. Graphical abstract